Various naphthalimide compounds have been developed for use as dyes and optical brightening agents. Kimura et al., for example, at Chem. Abst., Vol. 62, 11950c, disclose N-[2-piperidinoethyl]-4-methoxy-1,8-naphthalimide (i.e. 6-methoxy-2-[2-(1-piperidinyl)ethyl]-1H-benz[de]isoquinoline-1,3(2H)-dione under the current Chem. Abst. nomenclature) as an optical brightening agent. Noguchi et al. in U.S. Pat. No. 3,625,947 disclose 2-[2-(2- or 4-pyridyl)ethyl]-1H-benz[de]isoquinoline-1,3(2H)-diones as fluorescent whitening agents.
Schenker et al. in U.S. Pat. No. 3,247,208 disclose that 1H-benz[de]isoquinoline-1,3(2H)-diones having a (1-substituted-4-piperidinyl) group in the 2-position possess anesthetic properties. Carron et al. in French Pat. No. 2,167,355 disclose that (4-phenyl)piperidine-2,6-diones having an alkylheteroalkyl substituent at the 1-position possess antidepressant activity. Imides having a nitroimidazolyethyl group as an N-substituent and possessing anti-bacterial and anti-protozoal activity are disclosed in U.S. Pat. Nos. 3,642,836 and 3,770,763 to Cusic et al. Certain imido dicarboxylic acid imides possessing various pharmacological properties are disclosed in U.S. Pat. No. 3,560,495 to Frankus et al.
Pharmaceutically active compounds having a 4-(2,3-dihydro-2-oxo-1H-benzimidazol-1-yl)-1-(piperidinyl or 1,2,3,6-tetrahydro-1-pyridinyl) substituent are disclosed by Janssen in U.S. Pat. Nos. 3,161,645, 3,196,157, 3,225,052, 3,318,900, and 3,345,364, by Janssen et al. in U.S. Pat. No. 3,818,017, by Maruyama et al. in U.S. Pat. No. 3,840,529 and by Soudijn et al. in U.S. Pat. No. 3,873,534.